Re-enable skipped test: Clipboard_SetDataObject_InvokeObjectBoolNotIComDataObject_GetReturnsExpected`

[vladimir-krestov]

• .NET Core Version: 7.0

• Have you experienced this same bug with .NET Framework?: No

Problem description:

• Test fails sometimes in CI build for successful PRs, that blocking deployment of fixes into sdk:
  Clipboard_SetDataObject_InvokeObjectBoolNotIComDataObject_GetReturnsExpected:
  Stack trace (comment):

Assert.Equal() Failure\r\nExpected: 1\r\nActual:   MemoryStream { CanRead = True, CanSeek = True, CanTimeout = False, CanWrite = True, Capacity = 70, ... }


Stack trace
   at System.Windows.Forms.Tests.ClipboardTests.Clipboard_SetDataObject_InvokeObjectBoolNotIComDataObject_GetReturnsExpected(Object data, Boolean copy) in /_/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ClipboardTests.cs:line 279

Expected behavior:

• All correct tests pass every time.

Minimal repro:

• Run CI build, it reproduces sometimes

[weltkante]

probably related to/duplicate of #3456

Clipboard is a machine-global resource and access needs to be serialized across multiple test classes. While we have a central test class for clipboard tests, there are the occasional API methods which indirectly modify the clipboard, and it will be nontrivial to find all tests that need to be executed sequentially.

[RussKie]

We probably ought to move all clipboard related tests to https://github.com/dotnet/winforms/tree/main/src/System.Windows.Forms/tests/IntegrationTests/UIIntegrationTests, as those are run serially.

[RussKie]

Related to #6269